What are the differences between brown bears and black bears? Objective *What are the differences between brown bears and black bears? *How does bear growth, development, and maturation compare to humans? Background Our "Bears of Glacier Bay" curricula unit is divided into three lesson plans, each taking one class session to complete. They are part of our "Middle School Scientists" series that explore the fascinating research and resources of Glacier Bay National Park. This is the first lesson in that series. Glacier Bay National Park is home to brown/grizzly bears ( Ursus arctos ) and black b Duration: 90 Minutes.